1. Field of the Invention
The present invention is in the field of metallurgy and relates in particular to the manufacture of non-ferrous metals such as aluminum.
2. Description of the Prior Art
Processes for the production of aluminum by thermal decomposition of pyrolysis of alkyl aluminum compounds have been suggested by K. Ziegler et al., U.S. Pat. No. 2,843,474 and by Ikeda et al., U.S. Pat. No. 3,154,407. In these processes, however, the actual production of aluminum is generally accompanied by the formation of a considerable amount of aluminum carbide as a by-product.
Formation of this undesirable aluminum carbide is discussed in an article by K. Ziegler et al., Annalen der Chemie, Vol. 629, Nos. 1-3, March 1960, p. 210-221, Metalloorganic Compounds XXXVIII "Pyrolysis of Al trialkyls" by Karl Ziegler, Konrad Nogel and Werner Pfohl.
The formation of the by-product, aluninum carbide, decreases the yield of aluminum produced by the thermal decomposition. It is also widely known in the manufacturing industry that the inclusion of a considerable amount of aluminum carbide in aluminum deleteriously effects the processability, corrosion resistance and other characterstics of the product aluminum.
One attack on the carbide problem is proposed by Tanaka et al., U.S. Pat. No. 3,170,787, wherein by regulating the rate of decomposition of the alkyl aluminum compound, the amount of carbide formed is controlled. Such a process requires a high degree of skill and is difficult to carry out effectively.
The present invention is directed to a process wherein these aluminum carbides can be readily removed with comparative ease.